Plane Trigonometry

Right Triangle

Area of Triangle

A = ½ ab


Complimentary Angles:


β + θ = 90°

Pythagorean theorem:

In any right triangle, the square of the longest side (hypotenuse) equals the sum of the squares of the other two sides.


c² = a² + b²

Trigonometric Functions of Right Triangle (SOH-CAH-TOA)

Relative to angle θ, a is the opposite side and b is the adjacent side.

Basic Trigonometric Identities:

Pythagorean Relations